1. Field of the Invention
The present invention relates to the structural support of utility channels in buildings. More specifically, the invention provides support for electrical conduits and is designed to be used during the concrete pouring phase of construction. It need not be retrieved once this phase is completed.
2. Description of Related Art
Numerous straps, harnesses, spacers, and supports have been devised to hold electrical conduits, communications channels, water pipes, air ducts, or other open portals. Most advancements have come by way of using new materials with fewer complicated or different parts. Because the space taken by these devices may account for some space that could be occupied by mechanical load bearing structures, it is desired that these devices be not obstructive, unduly large, or unwieldy. It would be advantageous to have them made of a single piece of material, because holding devices made of several pieces might tend to separate under pressure, stress, or strain.
The simpler the device is, the easier it will be to use. If such devices are used in quantity, the cost per item becomes increasingly important. It is also important on some applications to be able to use materials that can be buried in soil or left under the surface of poured concrete. Devices that will not expand or contract under temperature changes or corrode are preferred.
A conduit holder that is produced in one simple piece and will not corrode, expand, contract, or fall apart is desired. An inexpensive conduit holder that can remain under the surface of poured concrete is also desired. One or more of these attributes will be seen to be lacking with the patents referenced below.
U.S. Statutory Invention Registration No. H1012, issued on Jan. 7, 1992, to Clement A. Senatro, describes a clamp made in two pieces and three apertures in a vertical line such that each piece has half of each aperture. A single bolt holds both pieces together and both pieces to a substrate.
U.S. Pat. No. 2,622,123, issued on Dec. 16, 1952, to William M. Eakin, describes three apertures made from multiple pieces arranged in a triangular arrangement and the multiple pieces mutually exert a force on each other so as to hold the whole together. The bottommost piece is bolted into an external platform.
U.S. Pat. No. 3,095,042, issued on Jun. 25, 1963, to Edgar W. Clark, Jr., et al., describes three pieces of cylindrical tubing welded together on their external surfaces such that their axes are parallel. In spite of its apparent simplicity this device involves threaded inner surfaces, and was designed with a specific application in mind, i.e., joining tubing together and suspending the tubing inside an oil well casing. The device is not molded or cast from a single piece.
U.S. Pat. No. 3,526,934, issued on Aug. 20, 1970, to David H. Owen, Sr. describes a two-piece interlocking set of strips shaped with matching semicircular indentations meant to hold two electrical conduits. The two pieces connect via a tongue and groove method. There is no indication this device was meant to be submerged in concrete. A problem with two-piece interlocking conduit holders is that if one part gets warped or bent, the two strips can slip apart.
U.S. Pat. No. 4,602,760, issued on Jul. 29, 1986, to Karolyn L. Tiefenbach, et al., describes a bundle type clamp holding axially aligned cylindrical objects together in a particular relation to a static structure. This type of clamp was designed to be used with appliances or cars and not with structures. This device was not meant to be covered in concrete.
U.S. Pat. No. 4,618,114, issued on Oct. 21, 1986, to James H. McFarland, describes a conduit system supporting and clamping a series of conduits of different diameters in a parallel and spaced apart relationship maintained by vertically and horizontally interlocking modular units. Each unit consists of a frame member having at least one side including an arcuate surface corresponding to the outside diameter of a conduit. The conduit is supported on the arcuate surface of one frame member and clamped down by an interlocking member from above. The bottommost support is anchored to a floor or bottom of a recess. This device is applicable in the context of large systems and is not particularly useful for a small set of conduits about to be encased in concrete. This support system requires multiple parts.
U.S. Pat. No. 4,775,121, issued on Oct. 4, 1988, to James F. Carty, describes a plastic clamp used for attaching cables or wires to a wall. A support member and a retaining arm of rigid material are co-extruded with and connected by a flexible hinge member at one end of the support member and arm. A series of partitions extend inwardly from the support member toward the retaining arm; and each of these forms a support for a cable. A semi-rigid article like this was not meant to be encased in concrete.
U.S. Pat. No. 5,083,346, issued on Jan. 28, 1992, to Douglas O. Orton, describes a fastening assembly for elongate articles comprising a ring-shaped member and a non-deformable flexible strap. The strap goes around the outside of the two elongate articles with the ring in between the two. The strap goes through the ring in one direction after encountering the outside of one elongate article and through the ring in the other direction after going around the other elongate article. The free end of the strap is inserted through a ratchet slit on the other end of the strap. This device requires two pieces to produce.
U.S. Pat. No. 5,115,542, issued on May 26, 1992, to Michelle R. Gehres, describes a reusable hose separating clip made from an elongated piece of plastic unit including a hinge centrally located along the length of the clip. The clip is bent into two sides which are nearly mirror images of one another, but a latch on one side has to have something to latch into on the other. Along the edge where both sides come together, there are arcuate lengths alternating with flat lengths, but the top and bottom edges are mirror images with respect to these arcuate and flat portions. The arcuate lengths hold hoses, cables, conduits or support rods at the user""s discretion. This device may best be used with objects that have a variable cross-section such as a hose that can swell. The device might not be as efficient at holding conduits or rods because the opposite flat parts are not held rigidly together.
U.S. Pat. No. 5,316,247, issued on May 31, 1994, to Michael A. Wodka, describes a pole clip for arranging wires or other elongate objects around the circumference of a pole. The clip has a resilient and flexible hollow C-shaped body, such that the inner arcuate surface snaps to fit around a pole. The inner xe2x80x9cCxe2x80x9d and the nearly concentric outer xe2x80x9cCxe2x80x9d are radially connected at the ends and in the middle. This produces two symmetric hollow regions between the inner and outer C-shaped body. Small slits symmetrical with the C-shaped bodies allow elongate articles to be held about the pole. The elongate objects should be smaller in diameter than the pole in order to avoid distorting the shape of the clip.
U.S. Pat. No. 5,820,083, issued on Oct. 13, 1998, to Gerard G. Geiger, describes a tie mounting system for securing elongate items to a supporting structure. The mount is secured to the stud with a nut and washer, and provides an anchoring loop through which the tie can be looped to secure the tie and the items to the mount. This device is made from a number of parts. Because it is meant to be adjustable in view of its nuts and bolts, it is not meant to be covered with concrete.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.
The electrical conduit support is a single piece designed to hold two electrical conduits such that their lengthwise dimensions are parallel and their separation corresponds to the standard separation of apertures for conduits on electrical junction boxes. In its primary form, the electrical conduit support has two apertures to accommodate conduits and a third aperture for a support rod. The conduit support is produced in one piece from a thermoplastic material by injection molding, and is so inexpensive that it can be covered in concrete. Its physical properties are such that it will not be subject to significant thermal expansion or contraction. It will not corrode or set up corrosive reactions with nearby objects or other components of the support environment.
Accordingly, it is a principal object of the invention to provide an electrical conduit support which may be manufactured in one piece and can become a part of the internal support of a concrete structure.
It is another object of the invention to provide an electrical conduit support which is easy to install on a support rod or on two sections of conduit.
It is a further object of the invention to provide an electrical conduit support which can accommodate standard sizes of conduit with standard distances of separation.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.